Yoshihiro Takizawa

Immunohistochemical detection of heterophile Hanganutziu-Deicher antigen in human malignant melanoma

SummaryThe Hanganutziu-Deicher (HD) antigen is a heterophile antigen whose immunodominant molecule is N-glycolylneuraminic acid, a sialic acid that cannot be found in normal tissues of either humans or chickens. Using biotinylated chicken anti-HD antibody purified with affinity chromatography, expression of HD antigen was immunohistochemically investigated in formalin-fixed tissues of human malignant melanoma. HD antigen-positive melanoma cells were clearly demonstrated in 7 of 11 lesions of malignant melanoma. No HD antigen-positive cells were found in 8 lesions of melanocytic nevus, and no components of normal human skin including epidermal melanocytes were stained with the antibody. This study is the first that immunohistochemically demonstrates HD antigen in tissue sections of human malignant melanoma. The expression of the HD antigen in transformed human melanocytes may have great immunological significance because the antigen is absent from normal human tissues and is immunogenic in humans.

New immunodeficient (nude-scid, beige-scid) mice as excellent recipients of human skin grafts containing intraepidermal neoplasms.

Engraftment of normal or lesional human skin onto nude or SCID (severe combined immunodeficiency) mice has been used as an in vivo experimental model. However, this model has some limitations, such as shrinkage and loss of the grafted skin over time. To improve the experimental model, we have produced two new SCID-lineage mouse strains, BALB/cA-nude-scid (nu/nu, scid/scid) and BALB/cA-beige-scid (bg/bg, scid/scid) mice, by the method of cross intercross. Intraepidermal neoplastic lesions such as Bowen’s disease were grafted onto the back of the mice of these strains. The rate of reduction in the size of the grafts was lower on nude-scid and beige-scid mice than on SCID mice. Rates of survival of neoplastic cells in the grafts were higher in nude-scid mice than in SCID and beige-scid mice (SCID mice 38%, nude-scid mice 55%, beige-scid mice 38%). Neoplastic cells of Bowen’s disease grafted onto a beige-scid mouse proliferated and invaded the dermis during 233 days of observation, confirming the progression to invasive squamous cell carcinoma from carcinoma in situ. The present study revealed that nude-scid and beige-scide mice newly produced by us provide a very useful in vivo experimental model for the investigation of carcinogenesis and tumor progression in human skin.

Engraftment of precursor lesions of human cutaneous neoplasms onto C.B-17 SCID mice: a useful in vivo experimental model of carcinogenesis in human skin.

Using a full-thickness skin grafting technique, lesional skin from various human neoplastic and preneoplastic skin diseases was transplanted onto SCID (severe combined immunodeficiency) mice. Of 27 grafted lesions, 21 were successfully accepted by the mice and maintained in good condition. All these accepted grafts were finally excised 10–101 days after transplantation for histological examination. In most grafts, the characteristic histological configurations of each disease were well preserved. Immunohistochemical study using monoclonal antibodies to human blood group antigens ABH revealed that some elements of the grafts such as sweat glands were clearly positive, confirming that the tissue was from human skin. Neoplastic (atypical) cells were detected in 9 of 17 accepted grafts containing neoplastic cells from the beginning. The detection rates for neoplastic cells were very high (90%) in grafts from precursor lesions of squamous cell carcinomas such as Bowens disease (5/5 specimens) and thermal keratosis (2/3). In contrast, no definite neoplastic cells were found in two grafts from extramammary Pagets disease and five grafts from the radial growth component of malignant melanoma. In most of the grafts from latter two diseases, characteristic histological configurations such as elongation of the rete ridges were maintained, suggesting that the neoplastic cells were selectively eliminated from the grafts. Split-thickness grafts of normal human skin were accepted and remained in a good condition for as long as 6 months. Engraftment of human lesional and non-lesional skin onto SCID mice therefore may well provide a useful in vivo experimental model of human skin diseases.

Effective Antiscaling Performance of Reverse-Osmosis Membranes Made of Carbon Nanotubes and Polyamide Nanocomposites

The antiscaling properties of multiwalled carbon nanotube (MWCNT)–polyamide (PA) nanocomposite reverse-osmosis (RO) desalination membranes (MWCNT–PA membranes) were studied. An aqueous solution of calcium chloride (CaCl2) and sodium bicarbonate (NaHCO3) was used to precipitate in situ calcium carbonate (CaCO3) to emulate scaling. The MWCNT contents of the studied nanocomposite membranes prepared by interfacial polymerization ranged from 0 wt % (plain PA) to 25 wt %. The inorganic antiscaling performances were compared for the MWCNT–PA membranes to laboratory-made plain and commercial PA-based RO membranes. The scaling process on the membrane surface was monitored by fluorescence microscopy after labeling the scale with a fluorescent dye. The deposited scale on the MWCNT–PA membrane was less abundant and more easily detached by the shear stress under cross-flow compared to other membranes. Molecular dynamics simulations revealed that the attraction of Ca2+ ions was hindered by the interfacial water layer formed on the surface of the MWCNT–PA membrane. Together, our findings revealed that the observed outstanding antiscaling performance of MWCNT–PA membranes results from (i) a smooth surface morphology, (ii) a low surface charge, and (iii) the formation of an interfacial water layer. The MWCNT–PA membranes described herein are advantageous for water treatment.

Antiorganic Fouling and Low-Protein Adhesion on Reverse-Osmosis Membranes Made of Carbon Nanotubes and Polyamide Nanocomposite

We demonstrate efficient antifouling and low protein adhesion of multiwalled carbon nanotubes-polyamide nanocomposite (MWCNT-PA) reverse-osmosis (RO) membranes by combining experimental and theoretical studies using molecular dynamics (MD) simulations. Fluorescein isothiocyanate (FITC)-labeled bovine serum albumin (FITC-BSA) was used for the fouling studies. The fouling was observed in real time by using a crossflow system coupled to a fluorescence microscope. Notably, it was observed that BSA anchoring on the smooth MWCNT-PA membrane was considerably weaker than that of other commercial/laboratory-made plain PA membranes. The permeate flux reduction of the MWCNT-PA nanocomposite membranes by the addition of FITC-BSA was 15% of its original value, whereas those of laboratory-made plain PA and commercial membranes were much larger at 34%-50%. Computational MD simulations indicated that the presence of MWCNT in PA results in weaker interactions between the membrane surface and BSA molecule due to the formation of (i) a stiffer PA structure resulting in lower conformity of the molecular structure against BSA, (ii) a smoother surface morphology, and (iii) an increased hydrophilicity involving the formation of an interfacial water layer. These results are important for the design and development of promising antiorganic fouling RO membranes for water treatment.

A case of rapidly progressed burn scar cancer : squamous cell carcinoma mainly with Vimentin-positive undifferentiated and small-circular cells.

61歳女。左大腿後面の熱傷癈痕に数年前より結節を生じ徐々に増大。広範囲切除術施行後間もなく肺転移出現。PM療法・CDDP・VDS併用療法施行し, 一時的には奏効したが, 後に全身に転移が拡大し, 術後全経過7ヵ月程で死亡した。組織学的には, 小円形腫瘍細胞のびまん性の増殖が主体であるが, 一部には有棘細胞様細胞による胞巣も認められる。免疫組織化学的に, KeratinとVimentinの同一腫瘍細胞内の共存が確認されたことが, 特異であった。